Disappearing Input text value using Javascript

Hi,
I have an autocomplete javascript that works with an input text (HtmlInputText control).  I'm using Visual Studio 2012 (VB) and ASP.NET. Currently, the autocomplete works fine.  On the same aspx page, I have a button that when the user clicks, it will populate several textboxes based on the input text value.
Problem:  After populating the textboxes, the value that the user typed on the input text disappears!!!
How do I persist the input text value?  I'm using Session values and the Session value for the input text persists but it's just not being displayed.
Appreciate any suggestions/advice.